Weft tension for axminster looms



Sept. 17, 1946.

N. FLETCHER WEFT TENSION FOR AXMINSTER LOOMS Filed Feb. 3, 1945 2 Sheets-Sheet 1 p 9 'N. FLETCHER 2,4@7,773 v WEFT TENSION FOR AXMINSTER LOOMS Filed Feb. 3, 1945 2 Sheets-Sheet 2 Patented Sept. 17, 1946 UNITED STATES PATENT OFFICE WEFT TENSION FOR AXlVIINSTER LOOMS Norman Fletcher, Worcester, Mass., assignor to Crompton & Knowles Loom Works, Worcester, Mass., a corporation of Massachusetts Application February 3, 1945, Serial No. 575,991

8 Claims.

This invention relates to improvements in weft tensions for Axminster looms and it is the general object of the invention to provide a weft tension automatically controlled by the whip stick which takes up slack in the weft.

Axminster looms are customarily provided with a whip stick which takes up slack weft between the stationary package of yarn and the weft needle for the purpose of keeping the weft taut. A tension device located between the whip stick and the weft package is usually under control of a loom driven cam to apply and release tension at regularly recurring intervals during loom operation. The cam is usually so timed as to relieve tension when the weft needle is being inserted into the shed and then apply tension when the needle is being removed from the shed.

By such an arrangement the tensioning mechanism is under control of the loom driven cam with the result that if the loom should be stopped with the needle partly inserted into the shed the tension will be off and the whip stick can snap upwardly and create slackness in the weft. In wide looms which require the use of a long needle the eye end of the latter is subject to considerable vibration which may result in wrapping the weft around the needle should the latter come to rest during its insertion stroke. When the loom is again started up the weft breaks due to snarling at the needle eye.

It is an important object of my present inven tion to provide a tension which shall be under control of the whip stick throughout the loom operation and independently of the position of the needle. In this way I am able to make the operation of the tension conditional upon the position of the whip stick and dispense with the aforesaid cam and the several connecting parts between it and the tension, and I am also able to keep the thread taut during upward movement of the whip stick should the needle stop while passing into the shed.

In Axminster looms it is customary to use a weft guide near the inner end of the needle rail and associate this guide with a filling stop motion operative to stop the loom should the weft break. It is another object of my present invention to provide stopping mechanism which Will be operated by the whip stick when the weft breaks. In this feature of my invention the whip stick as it rises automatically effects application of tension to the weft with the result that the stick will stop at a normal raised position due to operation of the tension mechanism in holdin the weft provided the weft is intact. Should the thread break, however, the whip stick will not be restrained by the weft or the tension and will rise to an abnormally high position to close an electric switch to effect loom stoppage. In this way the whip stick serves not only to effect application of tension to stop itself at the normal raised position to permit continued loom operation, but also acts upon weft breakage to stop the loom.

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawings, wherein a convenient embodiment of my invention is set forth,

Fig. 1 is a diagrammatic view setting forth the relation between the fabric, the needle, the whip stick and stationary package of weft supply, together with my improved tension mechanism,

Fig. 2 is a front elevation of the needle rail and associated parts and having my invention applied thereto,

Fig. 3 is an enlarged front elevation of the tension mechanism showing the same in the position which it occupies when the needle is being inserted into the shed,

Fig. 4 is a view similar to Fig. 3 but showin the conditions existing when the whip stick is raised to its normal position,

Fig. 5 is an end elevation looking in the direction of arrow 5, Fig. 3, and

Fig. 6 shows diagrammatically a circuit which can be used to effect loom stoppage.

Referring to Fig. 2, I have shown a framework It normally extending to the right of the loom designated at H. The framework ll] supports a needle rail 12 along which slides a carrie l3 to which is attached the needle N. Any approved driving mechanism for the needle may be employed, such as a cable l4 wrapped around a drum I5 which receive oscillating motion from a rack l6 and a pinion IT. The cable is trained around pulleys l8 and is then attached to the needle carriage l3. During normal loom operation the rack and pinion oscillate the drum l5, causing the needle first to move into and then out of the warp shed, these movements corresponding to a movement to the left and then to the right as viewed in Fig. 2.

The weft W is supplied by a stationary package 20 and is led through a tension mechanism described in detail hereinafter and designated generally at T. From the tension mechanism the weft leads to an eye E in a whip stick 2|. A pair of eyes 22 of usual form are mounted on the inner or left end of the needle rail as viewed in Fig. 2, and serve as guides for the weft W. It has been customary in the past to associate the guides 22 with a filling or weft stop motion, but it will be understood from the following description that this stop motion may be omitted inasmuch as its function is performed by a part of my invention.

Referring particularly to Fig. 1, the fabric F has right and left selvages S and S, respectively, from which extend rearwardly the binder warps B which form the shed. 'A selvage shuttle 23 of usual form is located at the left side of the loom and cooperates with the needle N when the latter is fully inserted into the shed to form the selv'age' is. As the needle moves tothe left as viewed in Fig. l the weft which is attached to selvage S unwinds from package 29 and passes through tension T, eye E, guides-22 and to the needle N. After the weft is caught by the shuttle 23 the needle N is moved to the right during which movement there is no need for additional weft.v

While the needle is being inserted into the shed it places the weft'W under considerable tension with the result that the whip stick 2! moves down to the :dotted line position shown in Fig. 2, but upon withdrawal of the needle when the demand for weft has temporarily ceased the whip stick rises to the normal raised position shown in full lines, Fig. 2.

The matter thus far described of itself forms from eye 40 to eye 4! must pass between the pads 43 and 44 and be subject to any pressure which these pads may exert upon it. In order that the frictional force exerted by the pads 43 and 44 upon the weft may be varied, I employ a spreader arm 50 pivoted at 5! to the support 3| and having the end thereof remote from pivot 5! formed wedge shaped as indicated at 52, Fig. 5. A stud 55 on head 34 is spaced to the right of the axis of stud 33 and has pivoted thereto the upper end of a connector 55. The lower end of connector 56 is pivoted to a second stud 57 carried by the spreader arm 50.

When the whip stick is in its normally raised position as indicated in full lines in Fig. 2 the link 5'6 depresses arm 50 and moves the wedged part 52 thereof downwardly out of operative relation with respect to the pads 43 and 44. Under these conditions the spring 46 pushes the plate 43 rearwardly against the weft, exerting a resistance to movement of the weft between eyes no part of my present invention except as indicated hereinafterand may operate and be constructed in the usual manner.

In carrying my invention into'effect I provide the needle rail "with a rearwardly projecting st-and St to which is secured "an upright support '3! This support is provided'withan upper bearing 32 in which is rotatively mounted a stud 33 the forward end of which has secured thereto a head 34 to which the whip stick 2! is held by means of a clamp plate 35. An arm secured to the rear end of the stud 33 is attached to the upper end of a tension spring 3! the lower end "of which is connected to a lug 38 projecting rearwardly from the support 3!. The effect of the spring 3? is to tend to turn the stud, head and whip 'sti'c-k'in a right hand direction as viewed in Fig. 3, but the spring will'yield to permit downward movement of the whip stick.

Mounted on the support 3! are right and left guide eyes 4% and 4!, respectively, preferably made of some wear resisting material, such as porcelain, and through which the weftW passes. A stud '42 is mounted on and projects forwardly from the support 3'! and is surrounded by front and back tension pads or plates 43 and 44, respectively, mounted loosely on stud 42. The rear pad rests against a boss 45 on the support 3i, while the front pad 43 is 'slidably mounted on the stud 42 but is held normally in rear position by means of a compression spring 45 located between the front pad 43 and an adjusting nut 41 threaded onthest'ud 42. Spring 46 normally holds the stud 42 in the position shown in Fig. 5. A look nut 48 may be used to hold the nut 47 in any adjusted position. The purpose of the spring 46 is to tend normally to move the plate 43 rearwardly against plate 44, and by means of the nut 47 the force exerted by the spring 46 may be varied to alter the 'forc'e'exerted between the adjacent faces of the pads 43 and '44. v

The eyes 49 and 4! and the pads are related as shown in Fig. 3 so that the weft in passing and 4! dependent upon the amount of force exerted by spring 43. This is the condition which exists at the beginning of a weft inserting stroke of the needle, and as the latter moves into the shed not shown and creates demand for weft, the V whip stick will move down because of the fact that the weft is held by the pads 43 and '44. As the whip stick descends, however, link '56 lifts arm at and causes Wedge encl 5.2 to enter between the disks or friction plates and separate the latter by moving the front plate 43 forwardly against the action of spring 4%. This removes the tension force on the weft and the latter is free to move from the package '20 through the 'eyes 49 and 4-1 to the eye E of the whip stick and thence to the needle. So long as the needle continues moving toward the left as viewed in Fig. 1 there will be sufficient demand for weft to maintain the whip stick in down position and the tension will therefore be removed-from the weft.

As soon as the needle comes to rest in the shed preparatory to its removal the whip stick starts :to rise clue t'o operation-of spring 3 but in doing so acts through connector 56 to depress 'a-rm 5ll,

0 upward movement of the Whip stick is arrested.

From the matter thus far described it will be noted that the tension exerted on the weft by the pads 43 and 44 is conditioned in the sense that it is dependent for its operation upon the position of the stick and not upon the position of a regularly driven part acting in timed relation with the loo-m. It for this reason-that should the needle stop half way in the shed during its inserting stroke the whip stick will immediately rise and in doing so will cause spring :46 to exert a restraining force on the weft, holding the latter taut and thereby preventing the snarling which has existed heretofore in tension mechanisms dependent'uponacam. V V

The second feature of my invention relates to a stop mechanism operated by the whipstick and includes an electric switch 68 mounted on a horn 61 extending upwardly from the support 3!. This switch has an arm 62 which is above the whip stick when the 1atter is in its normal raised position. Under operation when the thread is intact the whip stick rises and falls without contacting the arm 62 due to the fact that the tension mechanism is controlled by the Whip stick as the latter rises and stops upward movement of the whip stick before it strikes the arm 62, the far end of the weft being held at selvage S. If, however, the weft thread should break at any point to the left of the'tension mechanism as viewed in Fig. 1 it will reeve through the eye E of the whip stick and the latter will therefore be raised by spring 31 to an abnormally high position and strike arm 62 to cause closure of switch 60.

Fig. 6 shows diagrammatically a loom controlling circuit which may be used with switch 60. A solenoid 10 is normally deenergized and permits the shipper handle H to remain in operating position so long as switch 60 is open. When the weft breaks and the whip stick rises to the dot and dash line position shown in Fig. 6 to close switch 60, current flows in the following circuit: transformer 12, wire 13, switch 60, wire 14, solenoid Ill, and wire to ground G, and thence back to the transformer through grounded wire 16. The solenoid thereupon moves the shipper handle] I to stopping position.

From the foregoing it will be seen that I have provided a tension mechanism for the weft of an Axminster loom conditional for its operation throughout the loom cycle on the position of the whip stick and operated independently of any regularly moving part of the loom, such as a cam. It will also be seen that when a demand for weft is created at the beginning of the needle inserting stroke the whip stick will be depressed and effect a simultaneous release of the tension, thereby permitting the weft to pass freely from the package through the whip stick eye to the needle. If the needle should be arrested while moving into the warp shed the whip stick will be raised to take up any attendant weft slack and in rising will apply a braking force to the weft by means of pads 43 and 44. It will further be seen that the tension which is automatically controlled by the position of the whip stick operates to stop the whip stick in its upward movement at a position just below the arm 62 of the switch 60 when the thread is intact. If the thread should break, however, the spring 31 will cause an additional upward movement of the whip stick to cause closure of switch 60 to effect loom stoppage.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be limited to the details herein disclosed, but what I claim is:

1. In conditional weft tensioning and releasing mechanism for an Axminster loom having a whip stick through the eye of which weft extends from a stationary weft package to a weft inserting needle, the whip stick being normally raised and moving downwardly during weft inserting movements of the needle, 3, weft tension between said stationary package and said eye of the whip stick normally operative to prevent passage of weft from said package to the whip stick eye, and operating connections between the whip stick and said tension effective when the whip stick moves downwardly to alter said tension by a force derived from said whip stick and cause the tension to permit passage of weft from said package to the whip stick eye.

2. In conditional weft tensioning and releasing mechanism for an Axminster loom having a whip stick through the eye of which weft extends from a stationary weft package to a weft inserting needle, the whip stick being normally raised and moving downwardly during weft insertin movements of the needle, tension means normally operative to prevent movement of weft from the package to the whip stick eye, and control'means for said tension connected to and operated by the whip stick and operative when the whipstick moves downwardly to cause the tension to release the weft and operative whenthe whip stick returns to normal raised position to permit the tension to reestablish normal holding relationship with' respect to the weft.

3. In conditional weft tensioning and releasing mechanism for an Axminster loom having a whip stick through the eye of which weft extends from a stationary weft package to a weft inserting needle, the whip stick being normally raised and moving downwardly during weft inserting movements of the needle, a tension mechanism comprising clamp members between which the weft extends, said clamp members being normally close together and operative to prevent weft from passing from said package to the whip stick eye, and control means for the tension mechanism normally out of controlling relation with respect to said clamp members but caused to separate said clamp members by a force derived from the whip stick when the latter descends to permit weft to move from between said clamp members to the whip stick eye whenthe whip stick moves downwardly.

4. In conditional weft tensioning and releasing mechanism for an Axminster loom having a whip stick through the eye of which weft extends from a stationary weft package to a weft inserting needle, the whip stick being normally raised and moving downwardly during weft inserting movements of the needle, a tension mechanism comprising a pair of clamping pads between which the weft extends from said package to the whip stick eye, means normally holding said pads against the weft firmly enough to prevent said weft from moving from the package to the whip stick eye, and control mechanism operated by the whip stick and effective when said stick moves downwardly to separate said pads to permit weft to pass between them, said control mechanism being moved out of controlling position with respect to the pads by the whip stick when the latter rises to permit said means to cause the pads to reestablish holding relationship with respect to the weft.

5. In conditional weft tensioning and releasing mechanism for an AXminster loom having a whip stick through the eye of which weft extends from a stationary weft package to a weft inserting needle, the whip stick being normally raised and moving downwardly during weft inserting movements of the needle, tensioning mechanism comprising a pair of pads between which the weft passes from said package to the whip stick eye, a wedge operativ'ely connected to and moved by the whip stick, and resilient means normally holding the pads in position to prevent weft from passing from said tensioning mechanism to the whip stick eye, said wedge effective when moved by downward movement of the whip stick to separate said pads to permit passage between them of the weft and said wedge moving away from said pads when the whip stick rises to permit said resilient means to reestablish said normal holding relation of said pads with respect to the weft.

6. In conditional weft tensioning and releasing mechanism for an Axminster loom having a whip stick through the eye of which weft exwhen the said stick moves downwardly to move said tension mechanism to said other position and effective when said whip stick rises to permit said tension mechanism to return to said one position.

7. In conditional weft'tensioning and releasing mechanism for an Axminster loom having a whip stick through the eye of which weft extends from a stationary weft package to a weft inserting needleg the whipstick moving from the normal position thereof to an operating position during weft inserting movements of the needle, tension mechanism when in one position applying suflicient tensioning force to the Weft to prevent the latter from moving from said stationary package to the whip stick eye, and said tension mechanism when in another position relieving said tensioning force to permit weft to pass from 7 said package to said whip stick eye, and means operated by the whip stick and effective when the latter is in normal position to permit said tension mechanism to apply the first named force to the weft and efiective when the whip stick moves to operating position to move said tension mechanism by a force derived from said whip stick to said other position thereof to relieve the tensioning force on the weft.

8. In conditional Weft tensioning and releasing mechanism for an Axminster loom having a whip stick through the eye of which weft extends from a stationary weft package to a weft inserting needle, the whip stick moving from the normal position thereof to an operating position during weft inserting movementsof the needle, tension mechanism operative either to apply resisting force to the weft to preventthe latterfrom moving from the package to the whip stick eye :or relieve said resisting force to permit weft to pass from the package to the whip stick eye, and means operated by the whip stick as the latter moves from the normal position thereof to the operating position thereof and :back to said normal position to control said tension mechanism to effect application of said resisting force to the Weft when the stickis in normal position and relieve application of said resisting force to the weft when the whip'stic'k is in operating position.

NORMAN FLETCHER. 

